De Doncker et al. U.S. Pat. No. 5,047,913, which is assigned to the present assignee and is incorporated by reference herein, describes auxiliary circuitry known as the auxiliary resonant commutation pole, or phase leg, (ARCP) circuit for achieving soft-switching of the switching devices of a power converter. The ARCP circuit comprises auxiliary switching devices connected in series with an inductor and snubber capacitors. U.S. Pat. No. 5,047,913 describes a control method whereby the gating and conduction times of the converter's switching devices, in addition to those of the auxiliary devices, are controlled to ensure that the output voltage attempts to overshoot the positive and negative converter rail voltages during each resonant commutation cycle in order to achieve soft-switching of all the converter's switching devices.
Disadvantageously, ARCP control circuits are typically complex and hardware intensive. In addition, the control state sequencing in these circuits is external to the ARCP package, resulting in less-than-robust and bulky designs. Accordingly, it is desirable to provide a robust, high-efficiency, high-density control for the ARCP which involves a simple control method. Furthermore, it is desirable that such a control require less signal processing circuitry and exhibit fault tolerance.